Abstract
Objectives: The present study compared the performance of the Lumipulse G Sars-CoV-2 Ag kit with the TaqPath COVID-19 RT-PCR CE IVD kit.
Methods: The study was conducted on 4266 naso-oropharyngeal swabs. Samples were subjected to antigen RT-PCR tests for the detection of Sars-CoV-2 and related variants. Statistical analyses were conducted in R software.
Results: We found 503 positives (including 138 H69-V70 deletion carriers) and 3763 negatives by RT-PCR, whereas 538 positives and 3728 negatives were obtained by antigen testing. We achieved empirical and binormal AU-ROCs of 0.920 and 0.990, accuracy of 0.960, sensitivity of 0.866, specificity of 0.973, positive and negative predictive values of 0.810 and 0.980. We obtained a positive correlation between viral loads and antigen levels (R 2 = 0.81), finding a complete concordance for high viral loads (log 10 copies/mL > 5.4). Antigen levels > 222 pg/mL were found to be reliable in assigning positive samples (p < 0.01). Concerning variant carriers, antigen test detected them with the same accuracy as other positive samples.
Conclusions: Molecular and antigen tests should be evaluated regarding the prevalence of the area. In case of low prevalence, antigen testing can be employed as a first-line screening for the timely identification of affected individuals with high viral load, also if carriers of Sars-CoV-2 variants.
Keywords: Antigen test; COVID-19; Naso-oropharyngeal swabs; Sars-CoV-2 variants; Screening; Viral load.
【저자키워드】 COVID-19, Screening, SARS-CoV-2 variants, Viral load, antigen test, Naso-oropharyngeal swabs, 【초록키워드】 variant, RT-PCR, variants, Antigen, Prevalence, sensitivity, specificity, Concordance, Accuracy, SARS-CoV-2 variants, Viral load, TaqPath, RT-PCR test, Analysis, Naso-oropharyngeal swabs, Negative predictive value, R software, RT-PCR tests, carriers, oropharyngeal swabs, individual, positive correlation, high viral load, viral loads, statistical analyses, positive, carrier, positive sample, Complete, IVD, log, affected, Sample, evaluated, conducted, R 2, 【제목키워드】 Antigen, Comparative analysis, molecular test,